Silicon-Silicon Nitride Integrated Polarizing Beam Splitter Based on Vertical Coupling Structure

Abstract

The invention discloses a silicon-silicon nitride integrated polarization beam splitter based on a vertical coupling structure, including an input waveguide, a polarization beam splitting waveguide, a first output waveguide and a second output waveguide, and the input waveguide is connected to one end of the polarization beam splitting waveguide , the other end of the polarization beam-splitting waveguide is respectively connected to the first output waveguide and the second output waveguide, and the polarization beam-splitting waveguide is a three-layer structure composed of silicon-silicon nitride-silicon from bottom to top. The invention has a compact structure, has shorter lateral dimensions and longitudinal lengths, improves the integration of the device; has a higher polarization extinction ratio; has larger manufacturing tolerances, and has relatively low requirements on the precision of the photolithography process, greatly The process cost is reduced.

Description

technical field [0001] The invention relates to a polarization beam splitter, in particular to a silicon-silicon nitride integrated polarization beam splitter based on a vertical coupling structure. Background technique [0002] As people's demand for information exchange increases day by day, the optical communication system needs larger and larger transmission capacity and faster and faster processing speed, and the requirement for the integration degree of circuit and optical path is also higher and higher. The gradual application of 5G technology and high-speed optical interconnection in data centers make large-scale photonic integration the direction of future development. In recent years, photonic integrated circuits based on silicon-on-insulator (SOI) platforms have begun to gain widespread attention and applications, mainly due to the ultra-high refractive index difference between silicon dioxide and silicon, which can well confine the optical field. At the core lay...

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Problems solved by technology

[0003] However, the existing directional coupler-type polarization beam splitters have the following defects: First, the directional coupler is generally coupled by two parallel waveguides, and the size of the two waveguides needs to meet the phase matching condition of the mode, so generally The directional coupler has a relatively small manufacturing tolerance and has high requirements for manufacturing accuracy; secondly, the directional coupler is mainly a horizontal coupling structure, which requires two waveguides to be arranged laterally, so the horizontal size of the device is relatively large, and it is not suitable for large Disadvantages of photonic integration at scale

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